The present invention relates to a Schottky barrier diode using a nitride semiconductor material and an integrated circuit using the same.
Nitride semiconductors typified by GaN are being earnestly developed for application to electronic devices such as a field effect transistor (FET) and a Schottky barrier diode (SBD) by taking advantage of their merits such as a high breakdown voltage and a high saturated electronic velocity. An SBD is required to have a high breakdown voltage and a low on resistance, and in order to realize a high breakdown voltage in a conventional SBD using a silicon (Si) material, it is necessary to lower a carrier concentration and increase the thickness of a drift layer where a depletion layer extends in applying a backward bias voltage. The drift layer is, however, a region where electrons pass in applying a forward bias voltage, and hence, the on resistance is increased when the thickness of the drift layer is increased. On the contrary, when a nitride material such as GaN with a high breakdown voltage is used, an SBD can attain a high breakdown voltage even when the thickness of a drift layer is decreased, and therefore, such an SBD attains a low on resistance and a high breakdown voltage.